The invention relates to an assembly for providing an aligned stack of two or more modules in a stacking direction, and to a lithography system or a microscopy system comprising such an assembly.
In particular in a lithography system or a microscopy system, various functional elements are combined in order to project one or more beams emitted from a beam source onto a target. For example, a maskless charged particle lithography system, as disclosed in WO 2011/043668, comprises a charged particle optical column for focusing one or more beams onto a surface of a target. Said charged particle optical column comprises a charged particle beam source, a collimator lens, an aperture array, an array of condenser lenses, a beam blanker array, a beam stop array, a deflector unit and a projection lens array. All these functional elements are arranged in said charged particle optical column and need to be accurately aligned with respect to each other.
When building the lithography system or the microscopy system, the various functional elements are mounted in a frame. Although the accurate alignment of the functional elements with respect to each other provides a challenge on its own, this alignment should in addition at least substantially be impervious to thermal expansion or contraction of the functional elements and/or the frame.
It is an object of the present invention to provide a lithography or a microscopy system wherein the functional elements are arranged in two or more individual modules, which modules are arranged in a stack with high accuracy and preferably wherein the alignment of the functional elements is at least substantially independent from temperature variations.